studentkra
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- studentkra
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My project of HMC253 and ESP8266 antenna switch on Github. https://github.com/studentkra/HMC253 Not tested yet ))
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Wow! Only 249 dollars. Good price!
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@n8oou Hello, Mike! I have never used the HMC253 before. I have also not studied the documentation for this product in detail. I have a need to switch two antennas to one RSP1A receiver. I used a switch on a relay, but at frequencies above 1500 MHz…
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I post firmware to control PE4302 attenuator via ESP8266 on GitHub now. https://github.com/studentkra/PE4302_attenuator
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I have an ESP running an attenuator right now. I wrote the program for ESP myself. Everything has been working fine for almost a year. It will not be difficult to rewrite the software for managing this switch. And I don't understand why to use a boa…
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I received an HMC253 (DC-2.5 GHz) board today for $8. I also have an ESP8266 for $2. These are the cheapest materials from which you can assemble an antenna switch controlled via USB. https://forum.kiwisdr.com/uploads/982/VRVE2OZL4W11.jpg
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Thank you, John! I was very very interested in investigating this. By the way, while the Kiwi server is not launched, the FPGA consumes about 60 mA. And by the way again ... I was offered to leave this Kiwisdr for myself. And I made a case for two r…
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Today I installed the TLV62569DBVR pulse stabilizer instead of the failed LMR10530Y. Their reference voltage is the same, so there is no need to change the voltage resistive divider. https://forum.kiwisdr.com/uploads/736/Z6RCNTUZ4S17.jpg I used an…
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John, thank you so much for your suggestion! But I want to try to repair the KiwiSRR on my own, using cheap and affordable components. As you can see, I have installed a linear stabilizer to power the FPGA 1.0V. It has been working fine for several …
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If you keep in mind which country I'm in, then I don't have any available options for buying these chips )) Or price is so high, so i can not let myself to by it. Alsow, look at min quanity of order ))
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The LMR10530 pulse stabilizer cannot be purchased. I've also been looking for analogues for a very long time, at least a little similar in pinout. It ended in failure. ChatGPT and DeepSeec couldn't help me either. I ordered several pieces of TLV6256…
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I also saw something similar on my KiwiSDR. This was due to the charger for a 12 volt car battery. I do not know what kind of charger it was, but I found out that the neighbor was charging the battery next to me. The KiwiSDR spectrum looked exactly …
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Please check the GPS fix. Instead of the set coordinates, my KiwiSDR is displayed in a real location on the map.
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Coil L403 has the lowest inductance of all four coils. Perhaps it is wound with thicker wire and therefore withstood the high current.
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Timestamps on the waterfall settings are not saved in the browser. However, you can use additional javascript.
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Yes, sure. But we already have an LPF in front of the preamp with a very steep decay level. And the filter in the differential output line of the preamplifier is just an addition. The decay level is very smooth since it is only first order. But in s…
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I tried a short-circuited inductor L401of filter in the simulator. The characteristics have not changed much, only starting from 24 MHz there is a slight attenuation of the signal. About 3dB at 30 MHz. Also, the short-circuited inductors L405 and L4…
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I carefully studied the photo and it seems to me that the copper paths of the input and output of the attenuator are cut. That is, attenuator is completely disconnected from the circuit.
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I assembled such a 5 volt power-on delay circuit on the NE555 chip. However, I had to use a MOSFET transistor to control the relay. The NE555 output voltage was not sufficient to turn on the relay. https://forum.kiwisdr.com/uploads/195/YTJVIKJ1F0JK.…
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All linear stabilizers work well. There is a slight difference in the noise introduced, but this is not significant. However, with large capacities there is a need for a delay in turning on the output power. When turned on, the capacitors do not hav…
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Let's finish it and delete this topic as it has no relevance to our KiwiSDR forum.
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Yes. This is bad frequency! Your should not listen it (((
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What input signal level can damage the PE4312? I'm ready to check it out. But I don’t have the necessary equipment (do I need a signal generator?) A similar attenuator PE4302 costs 0.8 USD (PE4312 1.4 USD) on Aliexpress including delivery.
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I successfully use an external attenuator for KiwiSDR1. The attenuator is assembled on the PE4302 board and ESP8266. Control is via USB connection to KiwiSDR. The attenuator works in a simple automatic mode. At night, a signal attenuation of 15 dB i…
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Hi! Look at this topic. https://forum.kiwisdr.com/index.php?p=/discussion/2942/24-hour-waterfall-capture
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On Saturday evening I finished installing the linear regulator in place of the LMR10530 and connected this KiwiSDR to the internet for an update. The default version was installed on BBB, as I was told. I'm not sure, but it was Debian 11 or 10 versi…
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I wanted to install a temperature sensor too. I found some NTC7717u sensors in SOT-23-5 package on old laptop motherboards. The sensor works on i2c bus and it would be easy to install it on KiwiSDR board. To display temperature KiwiSDR server reads …
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The LMR10530 had zero resistance between the power input and output after a thunderstorm. However, it also had a resistance of 5 Ohms to ground at the input and output. Perhaps this saved the FPGA.
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I have long wanted to try replacing the SMPS LMR10530Y with a linear one. Since this SMPS is out of order and I do not have the opportunity to buy an original or an analogue, I still used a linear one based on the uPC7706. Measured current consumpti…
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Martin, thank you. I'll think about replacing my LT1084 with LM338 . No changes to the adj schematic are required. They have the same reference voltage.